End stop for sliding clasp fasteners

ABSTRACT

A sliding clasp fastener is provided at the bottom end thereof with an end stop for restricting the movement of a slider thereat. The end stop comprises a thermoplastic strip of substantially square shape having a width corresponding substantially to a distance between the side flange ends of the slider, said strip further including an elongate tongue fused together with a group of interengaged fastener elements without interferring the sewn seam which secures the elements to the fastener tapes.

[451 Dec. 31, 1974 United States Patent [191 Ebata 3,435,489 4/1969 Morin.............. 3,482,292 12/1969 Frohlich...........

[54] END STOP FOR SLIDING CLASP FASTENERS [76] inventor:

3,672,008 6/1972 Mnele1a[...........

Shmkanaya UOZushl Toyama' Primary Examiner-Roy D. Frazier Kenjapan Assistant Examiner-Darrell Marquette July 17, 1973 Attorney, Agent, 0r Firm-Frank J. Jordan [22] Filed:

[2l] Appl. No.: 379,964

to the fastener tapes.

5 Claims, 3 Drawing Figures 24/205.1 l 24/205.l l

UNITED STATES PATENTS 2,220,136 ll/l940 Marinsky...................... 3,309,746 3/1967 Carlile..........................

END STOP FOR SLIDING CLASP FASTENERS BACKGROUND OF THE INVENTION This invention relates to sliding clasp fasteners and Amore particularly to an improved end stop for use in restricting the movement of the slider thereof.

A sliding clasp fastener contemplated in the practice of the invention comprises a pair of oppositely disposed Stringer tapes each carrying along their respective longitudinal edges a row of interlocking fastener elements formed from a continuous plastic filament into a spiral or meandering structure, and a slider arranged to move along the longitudinal edges of the Stringer tapes to take the fastener elements into and out of engagement with one another thereby closing and opening the fastener. To restrict the movement of the slider at a predetermined point on the fastener, there are usually employed end stops anchored in place at a top and a bottom end region of the fastener. It is to the bottom end stop which the present invention relates.

There are known different types and forms of bottom end stops for preventing the slider from running off the rows of fastener elements. One such known end stop is formed by simply melting a group of plastic fastener elements together adjacent the bottom end of the fastener. Another end stop known in the art is formed by also melting or fusing a plastic film together with the fastener elements, and causing the molten material to spread over the full width of the fastener, with a stopper element formed at the upper end of the molten region. There is further known an end stop which consists of a relatively narrow plastic film fused to impregnate the fastener over its entire width and a stop member projecting centrally of the impregnated area for engagement with the slider.

The first mentioned prior art end stop has the disadvantage that it is liable to excessive wear or damage from repeated abutting engagement direct with the neck of the slider connecting its wing members and hence has very short service life.

The aforementioned second end stop is arranged such that the stopper element is brought into impinging contact with the flange end of the slider, with the results that it is often separated from the fastener tape. Since the plastic film is applied to the entire width of the fastener` this area of the fastener tape becomes stiff, rendering it difficult to run a sewing stitch therealong.

The third known end stop has the drawback that the fastener is susceptible to flexing about the border defined between the plastic impregnated region and nonimpregnated region of the fastener where the sewn stitches are restricted to move and hence are liable to become torn off or damaged.

A further disadvantage which is common to the various conventional end stop devices is that when the chain of interlocking fastener elements is broken off, it is extremely difficult to bring the chain completely back into meshed condition.

SUMMARY OF THE INVENTION Whereas, it is the primary object of the invention to eliminate most, if not all, of the above difficulties of the prior art end stops.

A more specific object of the invention is to provide an improved bottom end stop for sliding clasp fasteners which is held securely in place against displacement or separation from the fastener in repeated abutting engagement with the slider.

Another specific object of the invention is to provide an improved bottom end stop which is constructed such that the sewn stitches located adjacent to the end stop are held immune from damage when the fastener is bent or flexed.

A further specific object of the invention is to provide an improved end stop which has structural features to permit the slider, when the fastener cracks open unintentionally, to take the disengaged fastener elements backinto normal engagement with one another with utmost ease.

These and other objects and features of the invention will be better understood from the following detailed description of a preferred embodiment of the invention taken in conjunction with the accompanying drawings in which like reference numerals refer to like or corresponding parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a sliding clasp fastener on which an end stop embodying the invention is mounted, the fastener being shown as in closed disposition;

FIG. 2 is a transverse cross-sectional view taken on the line II--II of FIG. 1; and

v FIG. 3 is a plan view of the fastener which has been opened by a slider.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, there is shown a sliding clasp fastener 10 of the conventional type which comprises a pair of oppositely disposed stringer tapes 11,11, a row of fastener elements 12 secured by sewing threads 13 to the longitudinal inner edge of each tape l1 and a slider 14 mounted on the fastener for reciprocal movement along the opposed longitudinal edges of the Stringer tapes 11,11 to cause the fastener elements l2 to come into and out of engagement with one another in the usual manner.

The fastener elements 12 are made from a continuous plastic filament and formed into a spiral structure as shown. The slider 14 partly shown in FIG. 3 is of the usual construction consisting generally of spaced-apart upper wing (not shown) and lower wing 15, respectively, inwardly bent to form side flanges 16,16 and connected by a neck 17 in such a manner as to provide substantially a Y-shaped channel for guiding the movement of the fastener elements 12 therethrough.

Designated at 18 is a bottom end stop provided in accordance with the invention. which end stop is adapted for restricting thereat the downward movement of the slider 14 when the latter is manipulated to open the fastener 10. The bottom end stop 18 is made of a plastic material such as a thermoplastic resin and is substantially square in shape. It has a width w substantially corresponding to a distance between the side flange ends 16',16' of the slider I4 and not exceeding a distance d between the opposed longitudinal lines of stitchings s on the two mated Stringer tapes 11,11 so as not to interfere with the sewing operation. The end stop 18 has a forward marginal end 18' disposed for abutting engagement with the flange ends l6,l6 of the slider 14.

In the practice of the invention, the end stop 18 is supplied in the form of a plastic chip of film at a desired location near the bottom end area of the fastener and secured thereto by means of a high-frequency heating, supersonic processing or the like whereby the chip or film is fused to encompass a group of interengaged fastener elements 12 and impregnate into the tapes 11,11.

According to an important feature of the invention, interengaged portions 12' of a group of fastener elements 12 immediately beyond the forward marginal ends 16',16 of the slider 14 are deformed by means of heat and pressure into a solid piece of tongue 19 which is joined integrally with the body of the end stop 18. The number of fastener elements 12 to be thus deformed corresponds preferably to those elements 12 which remain interengaged when the slider 14 has been moved down into abutment with the end stop 18 to fully open the fastener 10. This is advantageous, in the event of the fastener becoming cracked open or broken apart, in that the tongue 19 serves to orient the endmost fastener elements into condition for ready reengagement with one another simply by bringing the slider 14 back to its starting position at the end stop 18. Another advantage accruing from the provision of the deformed group of elements or tongue 19 is that it reinforces the end stop 18 against severe stresses applied by the slider 14 and helps retain the positional stability of the end stop 18. At the same time the tongue 19, which is rigid to some extent while resilient, serves to prohibit the tendency of the fastener 10 to flex along the forward marginal end 18' of the end stop 18 which could otherwise occur and cause the stitches sto become torn y off or damaged.

There is further provided in accordance with the invention another tongue 20 extending from the rearward end of the end stop 18 in a direction opposite to the first-mentioned tongue 19. The tongue 20 is formed by deforming a group of elements 12 in the manner above described, and it is adapted to reinforce the end stop 18 against stresses imposed on the fastener 10 particularly in a direction to split apart the Stringer tapes 11,1 1.

What is claimed is:

l. In a sliding clasp fastener of the type which comprises a pair of oppositely disposed Stringer tapes each carrying along their respective longitudinal edges a row of interlocking fastener elements made of a continuous plastic filament and a slider having side flanges and mounted on the fastener for reciprocal movement along the said longitudinal edges, the improved bottom end stop for restricting the movement of the slider which comprises a thermoplastic strip laid overa group of fastener elements adjacent the bottom end of the fastener, means securing said strip to said fastener, said strip being substantially square in shape and having a width corresponding substantially to the distance between the side flange ends of the slider, and a tongue formed by deforming a group of interengaged parts of fastener elements adjacent to the forward marginal end of said square strip, said tongue being joined integrally with said strip.

2. A bottom end stop as defined in claim l wherein said group of interengaged fastener elements forming said tongue correspond in number substantially to those fastener elements which remain interengaged when the slider has been moved into abutment with said strip to fully open the fastener.

3. A bottom end stop as defined in claim l which further includes another tongue formed by deforming a group of fastener elements adjacent to the rearward marginal end of said square strip and joined integrally therewith.

4. A bottom end stop as defined in claim 1 wherein said strip is secured to said fastener by being fused to a group of interengaged fastener elements and impregnated with said tapes.

5. A bottom end stop as defined in claim l wherein said tongue is formed as a single elongated part extending integrally from a central portion of said strip and generally longitudinally aligned with the fastener elements when the latter are interengaged,

l l l l UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent No. 3,857,141 Dated December 31, 1974 Inventods) Hiroyuki EBATA It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Include in the heading that the Patent has been assigned to Yoshida Kogyo Kabushiki Kaisha, Tokyo, Japan.

Signed and sealed this 15th day of April 1975.

fittest:

C. 'tSlfL-UL A RUTE'E C. SON Commissioner of Patents ,flttesting Officer and Trademarks F ORM PO-1050 (10-69) USCOMM-DC 603764569 fr u.s. GOVERNMENT PRINTING omc: z un o-ass-su 

1. In a sliding clasp fastener of the type which comprises a pair of oppositely disposed stringer tapes each carrying along their respective longitudinal edges a row of interlocking fastener elements made of a continuous plastic filament and a slider having side flanges and mounted on the fastener for reciprocal movement along the said longitudinal edges, the improved bottom end stop for restricting the movement of the slider which comprises a thermoplastic strip laid over a group of fastener elements adjacent the bottom end of the fastener, means securing said strip to said fastener, said strip being substantially square in shape and having a width corresponding substantially to the distance between the side flange ends of the slider, and a tongue formed by deforming a group of interengaged parts of fastener elements adjacent to the forward marginal end of said square strip, said tongue being joined integrally with said strip.
 2. A bottom end stop as defined in claim 1 wherein said group of interengaged fastener elements forming said tongue correspond in number substantially to those fastener elements which remain interengaged when the slider has been moved into abutment with said strip to fully open the fastener.
 3. A bottom end stop as defined in claim 1 which further includes another tongue formed by deforming a group of fastener elements adjacent to the rearward marginal end of said square strip and joined integrally therewith.
 4. A bottom end stop as defined in claim 1 wherein said strip is secured to said fastener by being fused to a group of interengaged fastener elements and impregnated with said tapes.
 5. A bottom end stop as defined in claim 1 wherein said tongue is formed as a single elongated part extending integrally from a central portion of said strip and generally longitudinally aligned with the fastener elements when the latter are interengaged. 